something I would like to add that is in the same general venue. When you change your coolant. Instead of using tap water, use distilled water. Get 3 x 1 gallon jugs, what you have left over use for your battery ( if fillable).

Should always use distilled water. Yet, most people just use tap water whether it be from a well or city water.

What about needing to get the bleeders higher? I've seen many a folk talk about using a no spill funnel at the rad cap, or parking with the front of the car inclined, etc? I have an Alero with the same engine and am needing to bleed it. (I also have an 02 Impala which is why I'm joining this group.)

I just want to take the time to say thank you for posting this. I have been trying to fix this issue since the beginning of June, 2014. Needless to say, I am not a certified mechanic nor do I have as much knowledge as you do sir. I followed your instructions word for word and in less than 10 minutes I was done. My 2003 3.4 is running like a champ, blowing hot air, and maintaining proper operating temperature. Again, thank you for posting this as you have relieved over 7 months of stress and headaches. I will always be looking for your advice on here when I need help working on my car.

OK all this information is terrific but I have one more question. I have replaced the head gaskets, intake gaskets thermostat radiator and cap. The car is continuing to run on the high side of the normal range. Though it does not overheat the gauge is showing à higher value than I feel comfortable with. We put a laser thermometer on the inlet and outlet sides of the engine and both were under 190°. Should I be concerned with this? It actually runs slightly cooler at an idle then under load. I also have great heat at all times.?

If you get the car up to temp (at least 180) and then let it sit idling what does it get up to?

And what does it raise to once driving and under load? And what kind of load are we talking about? I mean obv full throttle or close to it constantly is going to raise the temp. But cruising at a stable speed should lower the temps and not raise them.

Also how did the coolant and old thermostat look as well as the lower intake (coolant passages)? Was there any sort of film/gunk build up?

Fyi: these engines do run a bit hot! As long as you are under 210f I wouldn't worry too much.

I run a Lower temp Tstat but only cause I don't live in a weird climate. I run a 180f stat and have yet to see 200f. But I am likely suffering on mpg because of it.

No gunk or film on lower or upper intake. The temp is slightly higher at cruising speed then at an idle. It does stay below the 3/4 mark on the gauge, but to me that is too high compared to what I have seen in my experience. When I speak of load, I am speaking of 60 to 65 mph.drove for 40miles and it never overheated and sitting at an idle for over 20 minutes the fans never came on. If this is common then I will just put a good set of gauges in rather then depend on the factory ones.

I agree gents! I would think if the engine was hot, the fans would come on. I will change the sending unit today. If ANYONE has anything that pops into their head I would appreciate any and all ideas! I have been working on engines for way too long and have never seen an engine run cooler at an idle then it does with air rushing through the radiator.
Nothing on this thing is easy to work on either! I guess being an old V8 guy I am very spoiled!

Well Gentlemen, Problem solved, the coolant temp sensor was bad. Though it was changed with the thermostat just before the head gaskets were changed it was failing. I thank you all for the quick and worthwhile info. I was beginning to doubt my own abilities and feared that I did something wrong with the head gasket job. Glad that wasn't it I couldn't even think about tearing that apart again! Again thanks to you all!